Johnson is a private dam located in Trempealeau, Wisconsin, along the Tr Elk Creek. Built in 1976 by the USDA NRCS, this earth dam stands at a height of 26 feet and spans a length of 380 feet. It serves as a water resource structure with a primary purpose categorized as "Other" and is funded, designed, and constructed by the Natural Resources Conservation Service.

With a maximum storage capacity of 40 acre-feet and a normal storage capacity of 17 acre-feet, Johnson has a low hazard potential and a moderate risk assessment rating of 3. While the condition assessment is not available, the dam is subject to inspection every 10 years. It features an uncontrolled spillway and outlet gates, indicating its limited control over water discharge.

Despite its relatively low hazard potential, Johnson plays a crucial role in managing water resources in the area. As a significant structure along Tr Elk Creek, this dam contributes to flood control and water storage efforts, showcasing the importance of maintaining and monitoring such infrastructure for the benefit of both the environment and the community.